In recent years the use of staples instead of sutures in surgical procedures has become more and more conventional. The use of staples saves a good deal of time over the use of sutures and therefore means that the patient has to spend less time under anesthesia and this is of great benefit to the patient.
Stapling instruments have also begun to be used in many intestinal procedures from the esophagus to the rectum. Here again a great deal of time is saved and some of the difficult procedures are made much simpler.
The above referenced applications describe and claim intraluminal anastomosis devices for use in various procedures such as, for example, where a section of colon has been excised and it is necessary to rejoin the remaining portion of the colon. The instruments of the above applications connect the two portions of the colon by means of a double row of staples.
In order to use the instrument above mentioned, each portion of the colon must be provided with a purse-string suture. This is usually done by hand with an appropriate suture and needle. This procedure is difficult and time-consuming and gives rise to a number of problems. If the stitches are too far apart, the infolded tissue can extend beyond the diameter of the anvil of the instrument. In such situation, a leak will develop after the tissues are stapled and excised from the instrument. Furthermore, if too large a cuff or margin of tissue is left beyond the purse-string suture line, there may be more tissue inside the instrument that it can accommodate. This makes it impossible to close the instrument to the proper gap setting for stapling and then the instrument may either not be operable or the staples may be formed too loosely or not at all. Any of the foregoing situations can cause serious problems and complications.
There is on the market a permanent reusable instrument marketed by U.S. Surgical Corporation for facilitating the placement of a purse-string suture in round hollow organs. This instrument is essentially a hemostat having two angulated bars centrally attached with interdigitating teeth. In the U.S. Surgical device, each of the bars has a through-hole through which a straight needle with a suture can pass. The intestinal tissue is inserted between the two bars with the interdigitating teeth and is clamped by those teeth into a convoluted configuration. As the needle passes through the hole in the upper bar it also passes through the tissue that has been forced between the teeth by the teeth on the lower bar, and vice versa.
This device is subject to a number of shortcomings. It is a common occurrence for the needle to pass through both sides of the flattened intestinal tissue, thus sewing the opposite sides together instead of putting in a purse-string stitch. Additionally, the tissue which is clamped can readily slide normal to the bars and this makes it very difficult to cut to provide a minimum even margin along the edge of the bars. Since this device is a permanent-type instrument, it must be carefully maintained and it must be sterilized for each procedure.
The purse-stringer described herein overcomes all of the above-mentioned shortcomings and objections by virtue of design features which will be described and also by being designed for pre-sterile disposable one-time use.